I have a Nutrafin KH test kit. The directions say fill tube and add 1 drop and shake. A blue color will result. Continue to add drops, shaking with each drop. When the color changes to yellow, stop. Multiply the total number of drops by 10 to determine the general hardness. My question is whats the ideal range ? The pamphlet says 105-125 mg/l, LFS I thought said it needs to be much higher ?????